Hi there.
I have setup like this:
Gateway (mikrotik) 10.0.0.4
DNS server (same) 10.0.0.4
DNS2 server (Win) 10.0.0.5
now, my clients have gateway 10.0.0.4 and dns 10.0.0.4, but, I want to disable Mikrotiks DNS cache, so I need firewall rulle which will redirect all requests to Windows DNS server, but I repeat I dont' want Mikrotik to be DNS server, and also I dont want to reconfigure all clients manualy so the DNS is 10.0.0.5.
Question is why I don't want Mikrotik as DNS server. Answer is that I think that there is a bug in DNS cache, it is always sending DNS requests to its DNS parrent, and it is consuming too much internet sometimes even 128kbit and here Internet is very expensive .